Manual tran 59 F100

[Roarkx]

Hello, looking for advice on changing the gear ratios on my standard 3 speed tran on 1959 F100 to make freeway speeds attainable at lower RPM's. What is the smartest way to go about this?

 

[Lukey]

The rear end should be a 9". Most Mid-late 70s trucks had 3.00 and numerically lower gears which would really help.